RESULTS: Researchers at France’s University Louis Pasteur, Strasbourg, and at Sirtris Pharmaceuticals have shown that resveratrol, a chemical component of red wine that has already been linked to longevity, protects mice against diet-induced obesity and insulin resistance and boosts their endurance, allowing them to run for twice as long as untreated animals before becoming exhausted. The researchers found that mice treated with resveratrol also had large, highly active mitochondria, the subcellular structures that convert nutrients into energy in almost all plants and animals. This effect was linked to activation of a gene called SIRT1, the mammalian equivalent of a gene known to influence life span in yeast.

WHY IT MATTERS: The findings may indicate the mechanism behind resveratrol’s life-extending effects: activating SIRT1 to boost metabolic function. If scientists can understand how to regulate the biochemical pathway that causes aging, they may be able to design drugs that can stop the diseases of old age.

METHODS: Mice fed a high-fat diet were given high doses of resveratrol (either 200 or 400 milligrams per kilogram of body weight, or the equivalent of about 8,000 to 16,000 glasses of red wine). The researchers then tested the resting metabolism, exercise capacity, and insulin sensitivity of the mice. They also used electron microscopy to study the size of the mice’s mitochondria and calculated differences in the expression of mitochondria-related genes in treated and nontreated mice.

NEXT STEPS: Sirtris Pharmaceuticals is conducting a clinical trial of a resveratrol­-like compound intended to treat type II diabetes.